FDA Approves Two New Melanoma Drugs

The US Food and Drug Administration (FDA) has approved two new medicines used to treat the most dangerous form of skin cancer, as well as a genetic test developed alongside those drugs.

The two new medications, both of which are manufactured by GlaxoSmithKline (GSK), are dabrafenib (which will be marketed as Tafinlar) and trametinib (which will be sold under the name Mekinist). They will be used to treat patients with advanced (metastatic) or unresectable (cannot be removed by surgery) melanoma, the FDA said.

According to Melissa Healy of the Los Angeles Times, The BRAF inhibitor Tafinlar would be used to treat patients whose tumors express a gene mutation known as BRAF V600E. The MEK inhibitor Mekinist can also be used to treat those individuals, as well as melanoma patients whose tumors express the BRAF V600K gene mutation.

“A genetic test developed alongside those drugs, and also approved by the FDA on Wednesday, will help physicians identify patients who could benefit most from the BRAF-inhibitor drugs,” Healy said. “The test is called the THxID BRAF test and is manufactured by BioMerieux of Grenoble, France.”

The two drugs have been approved for individual use and not as a combined treatment. However, Reuters reporters Ben Hirschler and Bill Berkrot note that GSK is conducting additional trials which they hope will demonstrate additional benefits from the drugs if they are taken together.

“After decades with virtually no progress in the fight against advanced melanoma and little to offer patients facing a virtual death sentence, Tafinlar and Mekinist mark the third and fourth new drugs approved by the FDA for metastatic melanoma in the past two years,” Hirschler and Berkrot said, adding that the approval of the two new medications is “a further step forward in targeted cancer care and will be used in patients with a specific genetic profile — an approach that will limit the number of people who get them.”

The FDA reports that Tafinlar was studied in 250 patients with BRAF V600E gene mutation-positive metastatic or unresectable melanoma. Study participants randomly received either the BRAF inhibitor or the chemotherapy drug dacarbazine, and those who took Tafinlar showed a 2.4 month delay in tumor growth versus those receiving dacarbazine.

Likewise, 322 skin cancer patients with the BRAF V600E or V600K gene mutation were randomly assigned to receive either Mekinist or chemotherapy during the trial. Patients receiving Mekinist had a delay in tumor growth that was 3.3 months later than those on chemotherapy.

“The most serious side effects reported in patients receiving Tafinlar included an increased risk of skin cancer (cutaneous squamous cell carcinoma), fevers that may be complicated by hypotension (low blood pressure), severe rigors (shaking chills), dehydration, kidney failure and increased blood sugar levels requiring changes in diabetes medication or the need to start medicines to control diabetes,” the FDA said in a statement.